Instrument for teaching telegraphic codes.



T. M. ST; JOHN.

INSTRUMENT FOR TEACHING TELBGRAPHIG CODES.

APPLICATION FILED AUG.8, 101p.

1,035,257, Patented Aug. 13, 1912.

Wihweboeo: M ZM %MM J M QWM- nected with switch lever 7.

THOMAS M. ST. JOHN, 013 NEW YORK, N. Y.

INb'IBUMEl TT FOR TEACHING TELEGRAPHIC CODES.

Specification of Letters Patent.

Patented Aug. 13, 1912.

Application filed August 8, 1910. Serial No 576,071.

To all whom it may concern:

Be it known that I, THOMAS M. ST. JOHN, a citizen of the United Statesof America, residing in the borough of Manhattan, city, county, andState of New York, have ,invented a certain Improved Instrument forTeaching Telegraphic Codes, of which the following is a specification.

In the accompanying drawing: Figure l is a diagram showing the pieces ofapparatus and appropriate circuit connections; Fig. 2, a plan view ofthe code plate; and Fig. 3 shows a modification. V

1 is an electromagnet of which 2 is the armature lever and 3 thearmature lever stop. This may be deemed to be an ordinary sounder. It isshown, however, so that it may be used also as a buzzer. On the armaturelever is the ordinary buzzer contact spring 4. One pole of the battery Bis connected through the windings of the magnet and by wire 5J0 one ofthe contact points 6 of a two-point switch 7. Wire 5 is connected to thefixed contact stop 3 cooperating with the spring 4 and switch contact 8is connected to the armature lever. The opposite pole of the battery isconnected to a plate 9 herein called the code plate and also to thelever 10 of a normally open Morse key. The bottom contact l l of the keyis connected to switch 7 which latter is also connected by a flexiblewire to a pointer 12. Preferably, the handle of the pointer is "ofinsulating material and may be of wood. It is only necessary that thepoint 12' should be con- When the switch is in the position shown in thedrawing, the key 10 may be operated according to the Morse or other codeand solid dots and dashes will be sounded by magnet 1. If the'switch,however, be transferred to the point 8, the magnet acts as a buzzer andthe dots and dashes have the characteristic sound of wireless telegraphsignals. The code plate 9 may, as in Fig. 2, e of metal having a facingor coating of'enamel or .other insulating -material through which areopenings exposing the surface of the plate. The widths of the exposedsurfaces correspond with dot and dash signals. For instance, the letter9 is shown as formed by two, narrow exposed surfaces of the metal platerepresenting two dots, then by a Copies of this patent may be obtainedfor five cents each, by addressing the wider exposed surtacerepresenting a dash and finally by 'a narrow exposed surfacerepresenting a dot. In this way, the entire alphabet of any e'odcinay berepresented. The constituent parts of each signal may be disposedvertically as shown in the draw-- ing or they might be horizont .lydisposed; and, if the plate shown is turned upon its side, they will behorizontally disposed. Now, if the learner draws the contact point 12across the exposed plate surfaces representing dots and dashes for theformation of any code character, the dots and dashes would be audiblyreproduced by the magnet either as solid (lots anddashes or buzzer (lotsand dashes-according to the position of switch 7.

lVith a little practice, one may quickly learn any dot and dash code. Ofcourse, the code plate may be prepared in any other way to effect theresult desired;'and, instead of the dots and dashes being formed by dotand dash impulses transmitted through the exposed metal surfaces of theplate, they may be formed by interruptions' of a closed circuit in whichcase the dot and dash characters on the plate would appear as areas ofinsulating material, as

indicated in Fig 3, which shows a section of the plate with thecharacters 9, 'w, r placed thereon inthe manner last described.

I claim: Telegraphic code teaching apparatus comprising a metal platewith a plane upper surface having insulating enamel dis-.1

posed thereon so as to form dot and dash patterns or characters thereoncombined with a conducting stylus, a source of electrical energy and asounder, a circuit including the aforesaid parts, buzzer contactsassociated with the sounder, a circuit connection including the buzzercontacts and a switch whereby when the switch i s in one position the,dot and dash signalsare produced by the buzzer action of the sounder andwhen in another position by the plain action of the sounder.

In testimony whereof, I have hereunto subscribed my name.

THOMAS M. ST. JOHN.

Witnesses:

LENA C. SrnAKnR, BLANCHE M. RUSK.

Commissioner of Patents,

Washington, D. C.

